Ground Fault
Yaskawa · E7 Drive
Hva betyr GF ?
The Drive output grounding current has exceeded 50% of the Drive's rated output current. This indicates a motor lead shorted to ground or a defective DCCT (Direct Current Current Transformer), posing risks of electrical shock, equipment damage, or fire.
Vanlige årsaker
- Insulation breakdown or short circuit between a motor phase winding (U, V, or W) and the motor frame or ground.
- Physical damage or insulation failure in the motor output cable, causing a short from a conductor to conduit, ground, or drive enclosure.
- Water ingress, condensation, or conductive contamination within the motor terminal box or the drive's output terminals (U, V, W).
- Failure of the internal DCCT (Direct Current Current Transformer) or current sensing circuitry within the drive.
- Incorrectly installed or damaged output filter (e.g., dV/dT filter, sine wave filter) causing excessive leakage current to ground.
Reparasjonssteg & Sjekkliste
Klikk på steg for å spore fremgangen.
- 1
Disconnect the motor leads (U, V, W) from the drive's output terminals and perform an insulation resistance test (megohm test) on each motor phase to ground.
- 2
Visually inspect the motor output cables for physical damage, chafing, or signs of moisture ingress, especially at cable glands and connections.
- 3
Measure the resistance between each output terminal (U, V, W) and the ground terminal (E/PE) at the drive with power off; any reading near 0 ohms indicates a direct short.
- 4
If the motor and cables test clear, temporarily remove any output filters or reactors and re-test the drive with a short cable to a known-good test motor, if possible.
- 5
Ensure the motor frame and the drive enclosure are correctly and securely connected to the main protective earth (PE) bus.
- 6
Verify that output cable shielding is properly terminated to the drive's ground terminal and the motor frame, where applicable.